Research on Rapid Assembly Technology of Helicopter Transmissions

Research and application of rapid assembly technology can widely improve the design efficiency of helicopter transmissions. An assembly model of helicopter transmissions is presented by introducing Geometric Constraint Graph (GCG) method. A hierarchical model is obtained by multi-shrink decomposition. A corresponding data structure is generated according to the hierarchical model. CATIA based a parametric component database is built up. The Assembly modelling software is implemented by using VB. Finally, a helicopter transmissions example is taken as application and the rapid assembly for helicopter transmission system is achieved.

Integrating an Electronics Component Database Into a Thermal Design Tool

When developing a thermal model of a highly populated electronics board, a significant amount of time and effort is needed to track the thermal characteristics of all the dissipating components. In business sectors where multiple boards are thermally designed and analyzed each year, developing a components database and integrating it into the analysis tool will save time and ensure that consistent values are used in every design. With an “in tool” component database, multiple advantages are achieved. Once a component is entered into the database, the component information can be accessed in subsequent designs that employ the component. All engineers doing thermal design have access to the database. Once the thermal characteristics of a component are agreed upon, consistency across all boards is maintained. Additionally, values for each component in the database can be automatically brought into the analysis tool. By making a computer program develop the model of the component, human error is removed. The database tracks all major thermal aspects of a component. This includes the maximum junction temperature, Theta JC (case to junction resistance), leg/pin configuration (size, length, number, conductivity), and board to case gap thickness. Optional values can include top side cooling resistance, performance temperature limits, manufacturer, datasheet web address, and even an entry to identify the configuring engineer.